From the past, there has been a technique of generating a stereoscopic video (3D video) that can be stereoscopically viewed by a user with use of videos of the same subject. Those videos are captured with two cameras installed in accordance with parallax of right and left eyes of the user.
As an example of the stereoscopic video imaging system, there is a system in which videos of reflected light and transmitted light are captured with right and left cameras through a half mirror mounted to a mount called rig. When a stereoscopic video is captured using a rig, it is necessary for the two cameras used to coincide with each other in settings thereof and to be synchronized with each other in order to prevent generation of a difference between videos captured with the right and left cameras.
In the related art, two cameras are connected to each other through a cable for transmitting a genlock (generator lock) signal (synchronization signal) that is used for synchronizing the two cameras. The two cameras synchronize processing frames of video signals thereof on the basis of the genlock signal. In addition, the two cameras are connected to each other through a cable for transmitting a time code signal that is used for synchronizing time codes of the two cameras. The time code is used for editing a moving image and the like. Generally, the time code is information on a time (hour, minute, and number of frames) from the start of shooting. The cable for the genlock signal and the cable for the time code signal each include two signal lines for input and output.
In another technique, as shown in FIG. 12, a camera 101 and a genlock signal generator 103 are connected to each other by a cable 104A, a camera 102 and the genlock signal generator 103 are connected to each other by a cable 104B, and the camera 101 and the camera 102 are connected to each other by a time code signal cable 105. Then, a genlock signal (Genlock in) generated in the genlock signal generator 103 is input to each of the cameras 101 and 102 so that the two cameras are synchronized with each other. In addition, an input and an output (TC in, TC out) of the time code signal are transmitted and received through the cable 105.
Further, in order to match camera setting values (shooting parameters) of two cameras with each other, a configuration file containing a setting value of one camera is stored in a memory card, and then the configuration file is called from the memory card by the other camera so that the settings of the two cameras are matched with each other. Alternatively, a camera operator needs to match the settings of the two cameras while comparing them with use of a menu or a remote operation apparatus (remote controller). Further, in order to almost simultaneously start recording in two cameras, a recording button of the camera main body or remote controller needs to be pressed at the same time in the two cameras.
To eliminate those inconveniences, Patent Literature 1 proposes the following technique.
In the technique disclosed in Patent Literature 1, when a main imaging apparatus is connected to another imaging apparatus via a communication means and a camera operator operates a first operation switch (presses a release button halfway down) of the main imaging apparatus, a shooting parameter value set for the main imaging apparatus is transferred to the other imaging apparatus so that a common shooting parameter value is also set for the other imaging apparatus automatically. Further, Patent Literature 1 discloses a technique of, when the camera operator operates a second operation switch (presses a release button all the way down), transmitting a shooting command to the other imaging apparatus and taking images at the same timing between those imaging apparatuses. With this technique, a shooting operation in a connection destination can be automatically performed almost at the same time as when a shooting operation with use of a main camera is performed.